Archive for the 'curves' Category

#51: Proper Press Fingerprinting takes Commitment

In this installment we will address the third question Dale raised in #47. Dale’s first two questions got answered in #48 and #49 which can be reviewed at JimRaffel.com.

Now, onto Dale’s third question:

3. In fingerprinting our presses, we’ve run up against the dreaded “Hurry up and do it, but don’t put too much work into it.” What are your recommendations for impressing upon the higher ups that doing color balancing and working out the calibrations takes time?

I would suggest you have your management read JimRaffel.com. The reality, however, is that the culture required for completing successful fingerprints starts at the top and does not get worked up from the bottom. I spent the better part of the first ten years of my career trying like heck to change the culture of a printing company (now out of business I might add) from the echelons of lower and middle management. While I hesitate to use the words “It can’t be done” (and not because my Mom the English teacher told me to never use contractions), I believe this is one place where this expression applies.

I have been very fortunate in my career. At 21 years of age before I had even graduated from RIT I was able to observe one of the pressruns used to set the early SWOP press standards. A lot of very smart people participated in this run and the scientific procedure was impressive. Then, not a year later I was the guy doing all the print quality measurements on a brand new Baker-Perkins G14 that cost about 9 million dollars back in 1986. While I was just one member of a very large team, the owner of the company made it quite clear that he was not making his first lease payment until we had a press that was printing correctly.

Over the next 3 years I had the same responsibility as 2 more new presses started up in that facility. In both cases, the purchase contract was very clear that we did not make lease payments until the press met our print quality standards. While the company in general had an difficult culture, in the case of all three of these press startups the message from the very top of the organization was “Do whatever it takes to get a solid press fingerprint.” The reason was simple, without a solid benchmark at startup how could we ever know what condition the press was in later?

Dale, it takes a great deal of time, money and a great team to perform a successful and meaningful press fingerprint. During the press startups above, the fingerprinting process could go on for a week or more. The press was fully crewed and lots of paper was run during this time. All the support staff had to be available from pre-press, plating, maintenance, materials handling, and more. I don’t think it’s an understatement to say that these fingerprint cost $100,000 or more.

Now, not all fingerprints need to cost that much. I took part in a very successful fingerprint within the last 30-days that probably cost no more than about $10,000 including our software and professional services time. It is, however, a matter of scale. The client for the 10K fingerprint was simply making the first investment in end-to-end color process control. All the key players in this organization participated in the meetings and remained on-site during the 2 (14 plus hour) days required to complete the fingerprint.

The results on the second day (and in follow-up calls the last three weeks) continue to be impressive. In the case above the press is not brand new but instead a fairly old and well worn pieces of iron which is now printing at an impressive level.

My conclusion is simple. If senior management of a PRINTING company is not willing to invest the time money and effort necessary to perform a proper PRESS fingerprint, one must really question the value of performing the fingerprint.

#32: Tales from the Press Trial (Part 2)

This week I will be providing more information about the MacDermid Printing Solutions Stabil-X press trial April 17th and 18th . This week I will review the variation data from two of the trial conditions:

  • STX opt – Stabil-X blanket run at optimum packing level
  • Press std – The set-up of the press when we arrived

The TVI graph from last week showed the mean 50% dot gain for the STX opt. to be 24.817 and the Press std. to be 25.556. In addition to the lower overall dot gain with the Stabil-X, the standard deviation of the Stabil-X opt. was only .752 compared with 1.088.

The density of the two runs are very similar as well as the associated standard deviations: STX opt. 1.489 and .018; Press std. 1.522 and .016.

Standard.jpg

Stabil-X.jpg

These two graphs plot each of the 10 samples measured for each trial condition. The graphs also show the mean as well as 3 standard deviation +/- control lines.

If you would like more information about the MacDermid Stabil-X blanket, please contact me and I will put you in touch with the right people at MacDermid.

#31 Tales from the Press Trial

On April 17th and 18th I had the pleasure of participating in a press trial with MacDermid Printing Solutions to evaluate the effectiveness of their new Stabil-X offset printing blanket. I am writing today about the TVI curve of the various trial conditions.

Stabil-X TVI

We ran five different conditions during the course of the trial. All the trials shown in the graph involved only one printing unit running magenta ink. The curves also represent the averaging of 10 press sheets. The five trial names and descriptions are:

  • STX opt - Stabil-X blanket run at optimum packing level
  • Press std - The set-up of the press when we arrived
  • STX -.003 - Stabil-X purposely under packed by 3 thousandths
  • STX +.002 - Stabil-X run at 2 thousandths over
  • STX +.004 Stabil-X run at 4 thousandths over

As one might expect the STX -.003 has not only the lowest TVI, but also a very poorly formed curve. A pretty good example of why you do not want to run your press under packed.

The Press std curve shows how this shop runs the press on a regular basis. Notice the hump in the TVI curve from 25 to 50%. Not an uncommon condition on many presses.

The STX opt curve is much smoother than the Press std curve, missing the hump from 25 to 50%. Also, run at virtually the same densities the dot gain (50%) and overall TVI is lower at all points than the normal press set-up.

Even the two STX over pack conditions produced smoother overall TVI curves than the press standard set-up. While the TVI is higher in most cases this is to be expected when adding that much squeeze to a blanket that really does not need it.

I will continue to write about this press trial for a least 2-3 more weeks. There is a great deal of data and information to still go over. I even have some sheets here I will be doing additional readings on.

If you would like more information about the MacDermid Stabil-X blanket, please contact me and I will put you in touch with the right people at MacDermid.

I still love the smell of ink in the morning

Over the coming weeks I will be writing a great deal about my last two days in Chicago. Kevin Kocher of MacDermid Printing Solutions (offset blanket manufacturer) invited me to a press trial of their new Stabil-X blanket. So, right about now if I was one of my readers I would be thinking how exciting can an off-set blanket be? In a word this blanket is cool. It truly is the first revolutionary technology change in blankets in decades. In short this blanket is a patented combination of a polymer backing (instead of fabric) with Kevlar fibers running through it as well as synthetic fibers to replace the nitrile rubber and cotton.

We took a great deal of measurements during this trial, and while I have not had time to fully review the data I can tell you that this blanket printed better. Better being lower dot gain at the same density levels as conventional blankets, a smoother shaped TVI curve than traditional blankets, and most importantly less density and dot gain variation in sequential pulls.

Over the coming weeks I will be including both numeric and graphical results of this test, showing how we utilized ColorMetrix to confirm the visual results with objective factual data.